java - 在无法识别的匿名类中实现的重写方法

Question

我有以下代码，摘自本教程:http://developer.android.com/training/volley/simple.html

        final TextView mResponse = (TextView) findViewById(R.id.response);
        RequestQueue queue = Volley.newRequestQueue(this);
        String url = "http://www.example.com/";

// Request a string response from the provided URL.
        StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
                new Response.Listener() {
                    @Override
                    public void onResponse(String response) {
                        // Display the first 500 characters of the response string.
                        mResponse.setText("Response is: "+ response.substring(0,500));
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                mResponse.setText("That didn't work!");
            }
        });

但是，尽管在匿名 Listener 类中实现了 onResponse() 方法，但 Response.Listener 仍带有红色下划线，并出现以下错误:“'Anonymous class derived from Listener' must either be declared abstract or在“Listener”中实现抽象方法“onResponse(T)””。我不确定为什么它没有看到我已经完全做到了。

Answer 1

Response.Listener 是一个通用类型。您必须指定:

new Response.Listener<String>()